leetcode Insertion Sort List

表示我觉得题目给的接口有点问题，还是我自己理解有问题。如果链表没有头节点，那么必须是传指针的引用啊！

下面贴代码：

#include 
  
   
#include 
   
     #include 
    
      #include 
     
       #include 
      
        #include 
       
         #include "ListNode.cpp" using namespace std; class Solution { public: ListNode *insertionSortList(ListNode*& head) { if (!head || !head->next){ return head; } ListNode* begin = head; ListNode* pre = begin; ListNode* cur = pre->next; begin->next = NULL; ListNode* tmp = begin; while (cur){ pre = begin; tmp = begin; while (tmp){ if (tmp->val > cur->val){ break; } pre = tmp; tmp = tmp->next; } ListNode* toInsert = cur; cur = cur->next; if (!tmp){ pre->next = toInsert; pre->next->next = NULL; } else{ if (pre == tmp){ toInsert->next = tmp; begin = toInsert; } else{ pre->next = toInsert; toInsert->next = tmp; } } } head = begin; } }; int main(){ ListNode* head = NULL; insert(head, 2); insert(head, 1); //insert(head, -1); Solution s; s.insertionSortList(head); print(head); }
       
      
     
    
   
  

但需要注意的是链表节点的截断，不过都比较基础，相信稍微想想大家都做得出来！